Robust: Thomas Vermaelen (right) shows his Arsenal colleagues the way with a strong challenge

Thomas Vermaelen believes Arsenal's comeback from two goals down to salvage a 2-2 draw with Barcelona in the Champions League last night was down to the Gunners' more physical approach in the second half.

Arsene Wenger's men were left staring into the abyss when Zlatan Ibrahimovic's quick-fire double left them 2-0 down shortly into the second half but rallied to claim a creditable draw thanks to strikes from Theo Walcott and Cesc Fabregas - a result that leaves them still in with a chance of progressing to the semi-finals.

And Vermaelen has a clear idea of how Arsenal must play in the quarter-final second leg at the Nou Camp next Tuesday if they are to stand any chance of qualification - get physical.

'It was a good comeback. We showed that we have been mentally strong this season,' Vermaelen said.

Double trouble: Zlatan Ibrahimovic celebrates one of his strikes at the Emirates

'Barcelona played well. They played their own game and created a few chances. It was difficult for us but if you go in at half-time 0-0 anything can happen.'

He added: 'After we went 2-0 down we were a little better physically. That was the change; we had more of the ball and there were more spaces on the pitch.'

An Arsenal triumph in Spain next week would complete one of the more unlikely comebacks in Champions League history but Vermaelen also insisted that the Gunners have every chance of emerging victorious, despit last night's result.

Back in the game: Theo Walcott scores against Barcelona on Wednesday night

'There are better results if you play first at home but you have to believe as a football player,' he said. 'Anything can happen and we go there with the full belief we can win.'

The defender added: 'We have to do what we didn't do very well in the first half – close them down more in midfield and play a little higher up the pitch. We didn't show them too much respect, we just didn't close them down – we gave them too much space.'